Communication method using context information of terminal in wireless communication system, and base station

ABSTRACT

Disclosed are a communication method and a base station, the communication method comprising: receiving, from a network entity, a message including context capability information and context type information of a terminal; transmitting, to the terminal, a context request message requesting the transmission of particular context information among the context information supported by the terminal; receiving, from the terminal, a context response message including the context information of the terminal; and changing configuration values of radio resources on the basis of the context information.

TECHNICAL FIELD

Following description relates to a wireless communication system, andmore particularly, to a method for a base station to performcommunication using context information of a user equipment in awireless communication system and the base station.

BACKGROUND ART

Wireless access systems have been widely deployed to provide varioustypes of communication services such as voice or data. In general, awireless access system is a multiple access system that may supportcommunication of multiple users by sharing available system resources(e.g., a bandwidth, transmission power, etc.). For example, multipleaccess systems include a Code Division Multiple Access (CDMA) system, aFrequency Division Multiple Access (FDMA) system, a Time DivisionMultiple Access (TDMA) system, an Orthogonal Frequency Division MultipleAccess (OFDMA) system, a Single Carrier Frequency Division MultipleAccess (SC-FDMA) system, and a multi carrier frequency division multipleaccess (MC-FDMA) system.

DISCLOSURE OF THE INVENTION Technical Problems

An object of the present invention is to propose a communicationmechanism using context information of a user equipment in a wirelesscommunication system.

Another object of the present invention is to provide a serviceappropriate for a user equipment in a manner that network entities aswell as an application server utilize context information of the userequipment.

The other object of the present invention is to efficiently utilize aradio resource by introducing a cloud scheme applied to a nextgeneration communication system.

The technical problems solved by the present invention are not limitedto the above technical problems and other technical problems which arenot described herein will become apparent to those skilled in the artfrom the following description.

Technical Solution

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, accordingto one embodiment, a method of performing communication, which isperformed by a base station using context information of a terminal in awireless communication system, includes the steps of receiving a messageincluding context capability information indicating whether or not theterminal provides context information and context type informationindicating a type of the context information supported by the terminalfrom a network entity, transmitting a context request message forrequesting specific context information among the context informationsupported by the terminal to the terminal, receiving a context responsemessage including context information, which is generated based oninformation generated in an application layer of the terminal, from theterminal, and changing a configuration value of a radio resource basedon the context information.

The changing step can further includes the steps of selecting differentbase stations related to the terminal based on the context informationand transmitting a resource reservation message for requestingreservation of a radio resource for the terminal to the different basestations.

The method can further include the steps of receiving a resourcereservation response message indicating that the reservation of theradio resource for the terminal is authorized from the different basestations and informing the terminal of the completion of the reservationof the radio resource.

The context information included in the context response message caninclude at least one selected from the group consisting of schedulinginformation, location information, and time information of a user of theterminal.

The reservation of the radio resource can be reserved for the terminalby a prescribed base station at a prescribed location at prescribed timeaccording to the context information included in the context responsemessage.

If a base station among the different base stations is unable to reservea radio resource according to the resource reservation message, the basestation may ask a network entity configured to manage radio resources toallocate an additional radio resource.

The network entity may correspond to an MME (mobility managemententity).

To further achieve these and other advantages and in accordance with thepurpose of the present invention, according to a different embodiment, abase station includes a transmitter, a receiver, and a processorconfigured to operate in a manner of being connected with thetransmitter and the receiver, the processor configured to receive amessage including context capability information indicating whether ornot the terminal provides context information and context typeinformation indicating a type of the context information supported bythe terminal from a network entity, the processor configured to transmita context request message for requesting specific context informationamong the context information supported by the terminal to the terminal,the processor configured to receive a context response message includingcontext information, which is generated based on information generatedin an application layer of the terminal, from the terminal, theprocessor configured to transmit a resource reservation message forrequesting reservation of a radio resource for the terminal to differentbase stations which are selected based on the context information.

ADVANTAGEOUS EFFECTS

As is apparent from the above description, the embodiments of thepresent invention have the following effects.

First of all, since it is able to perform communication using contextinformation of a user equipment, it is able to provide a user with aservice optimized to the user of the user equipment.

Second, since not only an application server but also network entitiesare able to utilize context information of a user equipment, the networkentities can organically operate with each other.

Third, since a radio resource is utilized according to contextinformation of a user equipment, it is able to reduce radio resourcewaste, thereby reducing cost of a service provider.

The effects of the present invention are not limited to theabove-described effects and other effects which are not described hereinmay be derived by those skilled in the art from the followingdescription of the embodiments of the present invention. That is,effects which are not intended by the present invention may be derivedby those skilled in the art from the embodiments of the presentinvention.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention. The technical features of the present invention are notlimited to specific drawings and the features shown in the drawings arecombined to construct a new embodiment. Reference numerals of thedrawings mean structural elements.

FIG. 1 is a diagram illustrating a brief structure of an evolved packetsystem (EPS) that includes an evolved packet core (EPC);

FIG. 2 is an exemplary diagram illustrating an architecture of a generalE-UTRAN and a general EPC;

FIG. 3 is an exemplary diagram illustrating a structure of a radiointerface protocol on a control plane;

FIG. 4 is an exemplary diagram illustrating a structure of a radiointerface protocol on a user plane;

FIG. 5 is a flow chart illustrating a random access procedure;

FIG. 6 is a diagram illustrating a connection procedure in a radioresource control (RRC) layer;

FIG. 7 is a diagram for V2X (vehicle to everything) communicationenvironment;

FIG. 8 is a flowchart for explaining an embodiment related to a proposedV2X communication method;

FIG. 9 is a flowchart for explaining a different embodiment related to aproposed V2X communication method;

FIG. 10 is a flowchart for explaining a further different embodimentrelated to a proposed V2X communication method;

FIG. 11 is a flowchart for explaining a further different embodimentrelated to a proposed V2X communication method;

FIG. 12 is a flowchart for explaining a further different embodimentrelated to a proposed V2X communication method;

FIG. 13 is a diagram illustrating a configuration of a node deviceaccording to a proposed embodiment.

BEST MODE Mode for Invention

Although the terms used in the present invention are selected fromgenerally known and used terms, terms used herein may be varieddepending on operator's intention or customs in the art, appearance ofnew technology, or the like. In addition, some of the terms mentioned inthe description of the present invention have been selected by theapplicant at his or her discretion, the detailed meanings of which aredescribed in relevant parts of the description herein. Furthermore, itis required that the present invention is understood, not simply by theactual terms used but by the meanings of each term lying within.

The following embodiments are proposed by combining constituentcomponents and characteristics of the present invention according to apredetermined format. The individual constituent components orcharacteristics should be considered optional factors on the conditionthat there is no additional remark. If required, the individualconstituent components or characteristics may not be combined with othercomponents or characteristics. In addition, some constituent componentsand/or characteristics may be combined to implement the embodiments ofthe present invention. The order of operations to be disclosed in theembodiments of the present invention may be changed. Some components orcharacteristics of any embodiment may also be included in otherembodiments, or may be replaced with those of the other embodiments asnecessary.

In describing the present invention, if it is determined that thedetailed description of a related known function or construction rendersthe scope of the present invention unnecessarily ambiguous, the detaileddescription thereof will be omitted.

In the entire specification, when a certain portion “comprises orincludes” a certain component, this indicates that the other componentsare not excluded and may be further included unless specially describedotherwise. The terms “unit”, “-or/er” and “module” described in thespecification indicate a unit for processing at least one function oroperation, which may be implemented by hardware, software or acombination thereof. The words “a or an”, “one”, “the” and words relatedthereto may be used to include both a singular expression and a pluralexpression unless the context describing the present invention(particularly, the context of the following claims) clearly indicatesotherwise.

The embodiments of the present invention can be supported by thestandard documents disclosed in any one of wireless access systems, suchas an IEEE 802.xx system, a 3rd Generation Partnership Project (3GPP)system, a 3GPP Long Term Evolution (LTE)/LTE-Advanced (LTE-A) system,and a 3GPP2 system. That is, the steps or portions, which are notdescribed in order to make the technical spirit of the present inventionclear, may be supported by the above documents.

In addition, all the terms disclosed in the present document may bedescribed by the above standard documents. In particular, theembodiments of the present invention may be supported by at least one ofP802.16-2004, P802.16e-2005, P802.16.1, P802.16p and P802.16.1bdocuments, which are the standard documents of the IEEE 802.16 system.

Hereinafter, the preferred embodiments of the present invention will bedescribed with reference to the accompanying drawings. It is to beunderstood that the detailed description which will be disclosed alongwith the accompanying drawings is intended to describe the exemplaryembodiments of the present invention, and is not intended to describe aunique embodiment which the present invention can be carried out.

It should be noted that specific terms disclosed in the presentinvention are proposed for convenience of description and betterunderstanding of the present invention, and the use of these specificterms may be changed to another format within the technical scope orspirit of the present invention.

First of all, the terms used in this specification can be defined asfollows.

-   -   UMTS (Universal Mobile Telecommunications System): a GSM (Global        System for Mobile Communication) based third generation mobile        communication technology developed by the 3GPP.    -   EPS (Evolved Packet System): a network system that includes an        EPC (Evolved Packet Core) which is an IP (Internet Protocol)        based packet switched core network and an access network such as        LTE and UTRAN. This system is the network of an evolved version        of the UMTS.    -   NodeB: a base station of GERAN/UTRAN. This base station is        installed outdoor and its coverage has a scale of a macro cell.    -   eNodeB: a base station of LTE. This base station is installed        outdoor and its coverage has a scale of a macro cell.    -   UE (User Equipment): the UE may be referred to as terminal, ME        (Mobile Equipment), MS (Mobile Station), etc. Also, the UE may        be a portable device such as a notebook computer, a cellular        phone, a PDA (Personal Digital Assistant), a smart phone, and a        multimedia device. Alternatively, the UE may be a non-portable        device such as a PC (Personal Computer) and a vehicle mounted        device. The term “UE”, as used in relation to MTC, can refer to        an MTC device.    -   HNB (Home NodeB): a base station of UMTS network. This base        station is installed indoor and its coverage has a scale of a        micro cell.    -   HeNB (Home eNodeB): a base station of an EPS network. This base        station is installed indoor and its coverage has a scale of a        micro cell.    -   MME (Mobility Management Entity): a network node of an EPS        network, which performs mobility management (MM) and session        management (SM).    -   PDN-GW (Packet Data Network-Gateway)/PGW: a network node of an        EPS network, which performs UE IP address allocation, packet        screening and filtering, charging data collection, etc.    -   SGW (Serving Gateway): a network node of an EPS network, which        performs mobility anchor, packet routing, idle-mode packet        buffering, and triggering of an MME's UE paging.    -   NAS (Non-Access Stratum): an upper stratum of a control plane        between a UE and an MME. This is a functional layer for        transmitting and receiving a signaling and traffic message        between a UE and a core network in an LTE/UMTS protocol stack,        and supports mobility of a UE, and supports a session management        procedure of establishing and maintaining IP connection between        a UE and a PDN GW.    -   PDN (Packet Data Network): a network in which a server        supporting a specific service (e.g., a Multimedia Messaging        Service (MMS) server, a Wireless Application Protocol (WAP)        server, etc.) is located.    -   PDN connection: a logical connection between a UE and a PDN,        represented as one IP address (one IPv4 address and/or one IPv6        prefix).    -   RAN (Radio Access Network): a unit including a Node B, an eNode        B, and a Radio Network Controller (RNC) for controlling the Node        B and the eNode B in a 3GPP network, which is present between        UEs and provides a connection to a core network.    -   HLR (Home Location Register)/HSS (Home Subscriber Server): a        database having subscriber information in a 3GPP network. The        HSS can perform functions such as configuration storage,        identity management, and user state storage.    -   PLMN (Public Land Mobile Network): a network configured for the        purpose of providing mobile communication services to        individuals. This network can be configured per operator.    -   Proximity Services (or ProSe Service or Proximity-based        Service): a service that enables discovery between physically        proximate devices, and mutual direct communication/communication        through a base station/communication through the third party. At        this time, user plane data are exchanged through a direct data        path without through a 3GPP core network (for example, EPC).    -   ProSe Communication: communication between two or more        ProSe-enabled UEs in proximity by means of a ProSe Communication        path. Unless explicitly stated otherwise, the term “ProSe        Communication” refers to any/all of the following: ProSe E-UTRA        Communication, ProSe-assisted WLAN direct communication between        two UEs, ProSe Group Communication and ProSe Broadcast        Communication.    -   ProSe E-UTRA Communication: ProSe Communication using a ProSe        E-UTRA Communication path.    -   ProSe-assisted WLAN direct communication: ProSe Communication        using a ProSe-assisted WLAN direct communication path.    -   ProSe Communication path: communication path supporting ProSe        Communication. The ProSe E-UTRA Communication path could be        established between the ProSe-enabled UEs using E-UTRA, or        routed via local eNB(s). The ProSe-assisted WLAN direct        communication path may be established directly between the        ProSe-enabled UEs using WLAN.    -   EPC Path (or infrastructure data path): the user plane        communication path through EPC.    -   ProSe Discovery: a process that identifies that a UE that is        ProSe-enabled is in proximity of another, using E-UTRA.    -   ProSe Group Communication: one-to-many ProSe Communication,        between more than two ProSe-enabled UEs in proximity, by means        of a common communication path established between the        ProSe-enabled UEs.    -   ProSe UE-to-Network Relay: is a form of relay in which a        ProSe-enabled Public Safety UE acts as a communication relay        between a ProSe-enabled Public Safety UE and the ProSe-enabled        network using E-UTRA.    -   ProSe UE-to-UE Relay: is a form of relay in which a        ProSe-enabled Public Safety UE acts as a ProSe Communication        relay between two or more ProSe-enabled Public Safety UEs.    -   Remote UE: This is a Prose-enabled public safety UE connected to        EPC through Prose UE-to-Network Relay without service from        E-UTRAN in a UE-to-Network Relay operation, that is,        Prose-enabled public safety UE configured to receive PDN        connection, whereas this is a Prose-enabled public safety UE        that performs communication with other Prose-enabled public        safety UE through a Prose UE-to-UE Relay in a UE-to-UE relay        operation.    -   ProSe-enabled Network: a network that supports ProSe Discovery,        ProSe Communication and/or ProSe-assisted WLAN direct        communication. Hereinafter, the ProSe-enabled Network may simply        be referred to as a network.    -   ProSe-enabled UE: a UE that supports ProSe Discovery, ProSe        Communication and/or ProSe-assisted WLAN direct communication.        Hereinafter, the ProSe-enabled UE and the ProSe-enabled Public        Safety UE may be referred to as UE.    -   Proximity: proximity is determined (“a UE is in proximity of        another UE”) when given proximity criteria are fulfilled.        Proximity criteria can be different for discovery and        communication.    -   SLP(SUPL Location Platform): entity that controls Location        Service Management and Position Determination. The SLP includes        SLC(SUPL Location Center) function and SPC(SUPL Positioning        Center) function. Details of the SLP will be understood with        reference to Open Mobile Alliance(OMA) standard document OMA AD        SUPL: “Secure User Plane Location Architecture”.

1. Evolved Packet Core (EPC)

FIG. 1 is a schematic diagram showing the structure of an evolved packetsystem (EPS) including an evolved packet core (EPC).

The EPC is a core element of system architecture evolution (SAE) forimproving performance of 3GPP technology. SAE corresponds to a researchproject for determining a network structure supporting mobility betweenvarious types of networks. For example, SAE aims to provide an optimizedpacket-based system for supporting various radio access technologies andproviding an enhanced data transmission capability.

Specifically, the EPC is a core network of an IP mobile communicationsystem for 3GPP LTE and can support real-time and non-real-timepacket-based services. In conventional mobile communication systems(i.e. second-generation or third-generation mobile communicationsystems), functions of a core network are implemented through acircuit-switched (CS) sub-domain for voice and a packet-switched (PS)sub-domain for data. However, in a 3GPP LTE system which is evolved fromthe third generation communication system, CS and PS sub-domains areunified into one IP domain. That is, in 3GPP LTE, connection ofterminals having IP capability can be established through an IP-basedbusiness station (e.g., an eNodeB (evolved Node B)), EPC, and anapplication domain (e.g., IMS). That is, the EPC is an essentialstructure for end-to-end IP services.

The EPC may include various components. FIG. 1 shows some of thecomponents, namely, a serving gateway (SGW), a packet data networkgateway (PDN GW), a mobility management entity (MME), a serving GPRS(general packet radio service) supporting node (SGSN) and an enhancedpacket data gateway (ePDG).

The SGW operates as a boundary point between a radio access network(RAN) and a core network and maintains a data path between an eNodeB andthe PDN GW. When. When a terminal moves over an area served by aneNodeB, the SGW functions as a local mobility anchor point. That is,packets. That is, packets may be routed through the SGW for mobility inan evolved UMTS terrestrial radio access network (E-UTRAN) defined after3GPP release-8. In addition, the SGW may serve as an anchor point formobility of another 3GPP network (a RAN defined before 3GPP release-8,e.g., UTRAN or GERAN (global system for mobile communication(GSM)/enhanced data rates for global evolution (EDGE) radio accessnetwork).

The PDN GW corresponds to a termination point of a data interface for apacket data network. The PDN GW may support policy enforcement features,packet filtering and charging support. In addition, the PDN GW may serveas an anchor point for mobility management with a 3GPP network and anon-3GPP network (e.g., an unreliable network such as an interworkingwireless local area network (I-WLAN) and a reliable network such as acode division multiple access (CDMA) or WiMax network).

Although the SGW and the PDN GW are configured as separate gateways inthe example of the network structure of FIG. 1, the two gateways may beimplemented according to a single gateway configuration option.

The MME performs signaling and control functions for supporting accessof a UE for network connection, network resource allocation, tracking,paging, roaming and handover. The MME controls control plane functionsassociated with subscriber and session management. The MME managesnumerous eNodeBs and signaling for selection of a conventional gatewayfor handover to other 2G/3G networks. In addition, the MME performssecurity procedures, terminal-to-network session handling, idle terminallocation management, etc.

The SGSN handles all packet data such as mobility management andauthentication of a user for other 3GPP networks (e.g., a GPRS network).

The ePDG serves as a security node for a non-3GPP network (e.g., anI-WLAN, a Wi-Fi hotspot, etc.).

As described above with reference to FIG. 1, a terminal having IPcapabilities may access an IP service network (e.g., an IMS) provided byan operator via various elements in the EPC not only based on 3GPPaccess but also on non-3GPP access.

Additionally, FIG. 1 shows various reference points (e.g. S1-U, S1-MME,etc.). In 3GPP, a conceptual link connecting two functions of differentfunctional entities of an E-UTRAN and an EPC is defined as a referencepoint. Table 1 is a list of the reference points shown in FIG. 1.Various reference points may be present in addition to the referencepoints in Table 1 according to network structures.

TABLE 1 Reference point Description S1-MME Reference point for thecontrol plane protocol between E-UTRAN and MME S1-U Reference pointbetween E-UTRAN and Serving GW for the per bearer user plane tunnelingand inter eNodeB path switching during handover S3 It enables user andbearer information exchange for inter 3GPP access network mobility inidle and/or active state. This reference point can be used intra-PLMN orinter-PLMN (e.g. in the case of Inter-PLMN HO). S4 It provides relatedcontrol and mobility support between GPRS Core and the 3GPP Anchorfunction of Serving GW. In addition, if Direct Tunnel is notestablished, it provides the user plane tunneling. S5 It provides userplane tunneling and tunnel management between Serving GW and PDN GW. Itis used for Serving GW relocation due to UE mobility and if the ServingGW needs to connect to a non-collocated PDN GW for the required PDNconnectivity. S11 Reference point between an MME and an SGW SGi It isthe reference point between the PDN GW and the packet data network.Packet data network may be an operator external public or private packetdata network or an intra operator packet data network, e.g. forprovision of IMS services. This reference point corresponds to Gi for3GPP accesses.

Among the reference points shown in FIG. 1, S2 a and S2 b correspond tonon-3GPP interfaces. S2 a is a reference point which provides reliablenon-3GPP access and related control and mobility support between PDN GWsto a user plane. S2 b is a reference point which provides relatedcontrol and mobility support between the ePDG and the PDN GW to the userplane.

FIG. 2 is a diagram exemplarily illustrating architectures of a typicalE-UTRAN and EPC.

As shown in the figure, while radio resource control (RRC) connection isactivated, an eNodeB may perform routing to a gateway, schedulingtransmission of a paging message, scheduling and transmission of abroadcast channel (BCH), dynamic allocation of resources to a UE onuplink and downlink, configuration and provision of eNodeB measurement,radio bearer control, radio admission control, and connection mobilitycontrol. In the EPC, paging generation, LTE_IDLE state management,ciphering of the user plane, SAE bearer control, and ciphering andintegrity protection of NAS signaling.

FIG. 3 is a diagram exemplarily illustrating the structure of a radiointerface protocol in a control plane between a UE and a base station,and FIG. 4 is a diagram exemplarily illustrating the structure of aradio interface protocol in a user plane between the UE and the basestation.

The radio interface protocol is based on the 3GPP wireless accessnetwork standard. The radio interface protocol horizontally includes aphysical layer, a data link layer, and a networking layer. The radiointerface protocol is divided into a user plane for transmission of datainformation and a control plane for delivering control signaling whichare arranged vertically.

The protocol layers may be classified into a first layer (L1), a secondlayer (L2), and a third layer (L3) based on the three sublayers of theopen system interconnection (OSI) model that is well known in thecommunication system.

Hereinafter, description will be given of a radio protocol in thecontrol plane shown in FIG. 3 and a radio protocol in the user planeshown in FIG. 4.

The physical layer, which is the first layer, provides an informationtransfer service using a physical channel The physical channel layer isconnected to a medium access control (MAC) layer, which is a higherlayer of the physical layer, through a transport channel Data istransferred between the physical layer and the MAC layer through thetransport channel Transfer of data between different physical layers,i.e., a physical layer of a transmitter and a physical layer of areceiver is performed through the physical channel

The physical channel consists of a plurality of subframes in the timedomain and a plurality of subcarriers in the frequency domain. Onesubframe consists of a plurality of symbols in the time domain and aplurality of subcarriers. One subframe consists of a plurality ofresource blocks. One resource block consists of a plurality of symbolsand a plurality of subcarriers. A Transmission Time Interval (TTI), aunit time for data transmission, is 1 ms, which corresponds to onesubframe.

According to 3GPP LTE, the physical channels present in the physicallayers of the transmitter and the receiver may be divided into datachannels corresponding to Physical Downlink Shared Channel (PDSCH) andPhysical Uplink Shared Channel (PUSCH) and control channelscorresponding to Physical Downlink Control Channel (PDCCH), PhysicalControl Format Indicator Channel (PCFICH), Physical Hybrid-ARQ IndicatorChannel (PHICH) and Physical Uplink Control Channel (PUCCH).

The second layer includes various layers. First, the MAC layer in thesecond layer serves to map various logical channels to various transportchannels and also serves to map various logical channels to onetransport channel. The MAC layer is connected with an RLC layer, whichis a higher layer, through a logical channel. The logical channel isbroadly divided into a control channel for transmission of informationof the control plane and a traffic channel for transmission ofinformation of the user plane according to the types of transmittedinformation.

The radio link control (RLC) layer in the second layer serves to segmentand concatenate data received from a higher layer to adjust the size ofdata such that the size is suitable for a lower layer to transmit thedata in a radio interval.

The Packet Data Convergence Protocol (PDCP) layer in the second layerperforms a header compression function of reducing the size of an IPpacket header which has a relatively large size and contains unnecessarycontrol information, in order to efficiently transmit an IP packet suchas an IPv4 or IPv6 packet in a radio interval having a narrow bandwidth.In addition, in LTE, the PDCP layer also performs a security function,which consists of ciphering for preventing a third party from monitoringdata and integrity protection for preventing data manipulation by athird party.

The Radio Resource Control (RRC) layer, which is located at theuppermost part of the third layer, is defined only in the control plane,and serves to configure radio bearers (RBs) and control a logicalchannel, a transport channel, and a physical channel in relation toreconfiguration and release operations. The RB represents a serviceprovided by the second layer to ensure data transfer between a UE andthe E-UTRAN.

If an RRC connection is established between the RRC layer of the UE andthe RRC layer of a wireless network, the UE is in the RRC Connectedmode. Otherwise, the UE is in the RRC Idle mode.

Hereinafter, description will be given of the RRC state of the UE and anRRC connection method. The RRC state refers to a state in which the RRCof the UE is or is not logically connected with the RRC of the E-UTRAN.The RRC state of the UE having logical connection with the RRC of theE-UTRAN is referred to as an RRC_CONNECTED state. The RRC state of theUE which does not have logical connection with the RRC of the E-UTRAN isreferred to as an RRC IDLE state. A UE in the RRC_CONNECTED state hasRRC connection, and thus the E-UTRAN may recognize presence of the UE ina cell unit. Accordingly, the UE may be efficiently controlled. On theother hand, the E-UTRAN cannot recognize presence of a UE which is inthe RRC_IDLE state. The UE in the RRC_IDLE state is managed by a corenetwork in a tracking area (TA) which is an area unit larger than thecell. That is, for the UE in the RRC_IDLE state, only presence orabsence of the UE is recognized in an area unit larger than the cell. Inorder for the UE in the RRC_IDLE state to be provided with a usualmobile communication service such as a voice service and a data service,the UE should transition to the RRC_CONNECTED state. A TA isdistinguished from another TA by a tracking area identity (TAI) thereof.A UE may configure the TAI through a tracking area code (TAC), which isinformation broadcast from a cell.

When the user initially turns on the UE, the UE searches for a propercell first. Then, the UE establishes RRC connection in the cell andregisters information thereabout in the core network. Thereafter, the UEstays in the RRC_IDLE state. When necessary, the UE staying in theRRC_IDLE state selects a cell (again) and checks system information orpaging information. This operation is called camping on a cell. Onlywhen the UE staying in the RRC_IDLE state needs to establish RRCconnection, does the UE establish RRC connection with the RRC layer ofthe E-UTRAN through the RRC connection procedure and transition to theRRC_CONNECTED state. The UE staying in the RRC_IDLE state needs toestablish RRC connection in many cases. For example, the cases mayinclude an attempt of a user to make a phone call, an attempt totransmit data, or transmission of a response message after reception ofa paging message from the E-UTRAN.

The non-access stratum (NAS) layer positioned over the RRC layerperforms functions such as session management and mobility management.

Hereinafter, the NAS layer shown in FIG. 3 will be described in detail.

The eSM (evolved Session Management) belonging to the NAS layer performsfunctions such as default bearer management and dedicated bearermanagement to control a UE to use a PS service from a network.. The UEis assigned a default bearer resource by a specific packet data network(PDN) when the UE initially accesses the PDN. In this case, the networkallocates an available IP to the UE to allow the UE to use a dataservice. The network also allocates QoS of a default bearer to the UE.LTE supports two kinds of bearers. One bearer is a bearer havingcharacteristics of guaranteed bit rate (GBR) QoS for guaranteeing aspecific bandwidth for transmission and reception of data, and the otherbearer is a non-GBR bearer which has characteristics of best effort QoSwithout guaranteeing a bandwidth. The default bearer is assigned to anon-GBR bearer. The dedicated bearer may be assigned a bearer having QoScharacteristics of GBR or non-GBR.

A bearer allocated to the UE by the network is referred to as an evolvedpacket service (EPS) bearer. When the EPS bearer is allocated to the UE,the network assigns one ID. This ID is called an EPS bearer ID. One EPSbearer has QoS characteristics of a maximum bit rate (MBR) and/or aguaranteed bit rate (GBR).

FIG. 5 is a flowchart illustrating a random access procedure in 3GPPLTE.

The random access procedure is performed for a UE to obtain ULsynchronization with an eNB or to be assigned a UL radio resource.

The UE receives a root index and a physical random access channel(PRACH) configuration index from an eNodeB. Each cell has 64 candidaterandom access preambles defined by a Zadoff-Chu (ZC) sequence. The rootindex is a logical index used for the UE to generate 64 candidate randomaccess preambles.

Transmission of a random access preamble is limited to a specific timeand frequency resources for each cell. The PRACH configuration indexindicates a specific subframe and preamble format in which transmissionof the random access preamble is possible.

The UE transmits a randomly selected random access preamble to theeNodeB. The UE selects a random access preamble from among 64 candidaterandom access preambles and the UE selects a subframe corresponding tothe PRACH configuration index. The UE transmits the selected randomaccess preamble in the selected subframe.

Upon receiving the random access preamble, the eNodeB sends a randomaccess response (RAR) to the UE. The RAR is detected in two steps.First, the UE detects a PDCCH masked with a random access (RA)-RNTI. TheUE receives an RAR in a MAC (medium access control) PDU (protocol dataunit) on a PDSCH indicated by the detected PDCCH.

FIG. 6 illustrates a connection procedure in a radio resource control(RRC) layer.

As shown in FIG. 6, the RRC state is set according to whether or not RRCconnection is established. An RRC state indicates whether or not anentity of the RRC layer of a UE has logical connection with an entity ofthe RRC layer of an eNodeB. An RRC state in which the entity of the RRClayer of the UE is logically connected with the entity of the RRC layerof the eNodeB is called an RRC connected state. An RRC state in whichthe entity of the RRC layer of the UE is not logically connected withthe entity of the RRC layer of the eNodeB is called an RRC idle state.

A UE in the Connected state has RRC connection, and thus the E-UTRAN mayrecognize presence of the UE in a cell unit. Accordingly, the UE may beefficiently controlled. On the other hand, the E-UTRAN cannot recognizepresence of a UE which is in the idle state. The UE in the idle state ismanaged by the core network in a tracking area unit which is an areaunit larger than the cell. The tracking area is a unit of a set ofcells. That is, for the UE which is in the idle state, only presence orabsence of the UE is recognized in a larger area unit. In order for theUE in the idle state to be provided with a usual mobile communicationservice such as a voice service and a data service, the UE shouldtransition to the connected state.

When the user initially turns on the UE, the UE searches for a propercell first, and then stays in the idle state. Only when the UE stayingin the idle state needs to establish RRC connection, the UE establishesRRC connection with the RRC layer of the eNodeB through the RRCconnection procedure and then performs transition to the RRC connectedstate.

The UE staying in the idle state needs to establish RRC connection inmany cases. For example, the cases may include an attempt of a user tomake a phone call, an attempt to transmit data, or transmission of aresponse message after reception of a paging message from the E-UTRAN.

In order for the UE in the idle state to establish RRC connection withthe eNodeB, the RRC connection procedure needs to be performed asdescribed above. The RRC connection procedure is broadly divided intotransmission of an RRC connection request message from the UE to theeNodeB, transmission of an RRC connection setup message from the eNodeBto the UE, and transmission of an RRC connection setup complete messagefrom the UE to eNodeB, which are described in detail below withreference to FIG. 6.

1) When the UE in the idle state desires to establish RRC connection forreasons such as an attempt to make a call, a data transmission attempt,or a response of the eNodeB to paging, the UE transmits an RRCconnection request message to the eNodeB first.

2) Upon receiving the RRC connection request message from the UE, theENB accepts the RRC connection request of the UE when the radioresources are sufficient, and then transmits an RRC connection setupmessage, which is a response message, to the UE.

3) Upon receiving the RRC connection setup message, the UE transmits anRRC connection setup complete message to the eNodeB. Only when the UEsuccessfully transmits the RRC connection setup message, does the UEestablish RRC connection with the eNodeB and transition to the RRCconnected mode.

2. V2X (Vehicle to Everything) Communication

FIG. 7 is a diagram showing a V2X (vehicle to everything) communicationenvironment.

If a vehicle accident occurs, many lives are lost and serious propertydamage is caused. Hence, the demand for a technology capable of securingpedestrian's safety as well as vehicle boarded person's safety isincreasingly rising. Hence, a vehicle-specified hardware and softwarebased technology is grafted onto a vehicle.

An LTE based V2X (vehicle-to-everything) communication technology havingstarted from 3GPP reflects the tendency of grafting an IT (informationtechnology) technology onto a vehicle. Connectivity function is appliedto some kinds of vehicles, and many efforts are continuously made toresearch and develop V2V (Vehicle-to-Vehicle) communication, V2I(Vehicle-to-Infrastructure) communication, V2P (Vehicle-to-Pedestrian)communication, and V2N (Vehicle-to-Network) communication throughevolution of communication functions.

According to V2X communication, a vehicle consistently broadcastsinformation on its own locations, speeds, directions, etc. Havingreceived the broadcasted information, a nearby vehicle utilizes theinformation for accident prevention by recognizing movements of othervehicles moving nearby.

Namely, in a similar manner that an individual person carries a userequipment in shape of a smartphone, a smartwatch or the like, a userequipment (hereinafter abbreviated UE) in specific shape is installed ineach vehicle. Here, a UE installed in a vehicle means a device actuallyprovided with a communication service from a communication network. Forexample, the UE installed in the vehicle can be provided with acommunication service by being connected to an eNB.

Yet, various items should be considered for a process for implementingV2X communication in a vehicle. This is because astronomical costs arerequired for the installation of traffic safety facilities such as V2Xbase station and the like. Namely, in order to support V2X communicationon all vehicle-movable roads, it is necessary to install hundreds orthousands of V2X base stations or more. Moreover, since each networknode accesses Internet or a central control server using a wired networkbasically for stable communication with a server, installation andmaintenance costs of the wired network are high.

Meanwhile, prior to the description of the proposed V2X communicationmethod, several kinds of terms to be used in the following specificationare defined first.

-   -   RSU (road side unit): This is an entity supportive of V2I        communication and means an entity capable of performing a        transmission/reception to/from a UE using a V2I application. The        RSU can be implemented in an eNB or UE (particularly, a        stationary UE). An eNB or UE operating as RSU collects        information (e.g., traffic light information, traffic volume        information, etc.) related to traffic safety and/or information        on nearby vehicle movement, transmits information to another UE        becoming a target of V2I communication, and receives information        from another UE.    -   V2I communication: This is a type of V2X communication. A UE and        RSU that use V2I application become main agents of the        communication.    -   V2N communication: This is a type of V2X communication. A UE and        serving entity that use V2N application become main agents of        the communication and communicate with each other through an LTE        network entity.    -   V2P communication: This is a type of V2X communication. Two UEs        that use V2P application become main agents of the        communication.    -   V2V communication: This is a type of V2X communication. Two UEs        that use V2V application become main agents of the        communication. V2V communication differs from V2P communication        in the following. In the V2P communication, a prescribed UE        becomes a UE of a pedestrian. In the V2V communication, a        prescribed UE becomes a UE of a vehicle.    -   Uu interface (or, E-UTRAN Uu interface): This means an interface        between a UE and an eNB defined in LTE/LTE-A. With respect to a        relay node, this interface may mean an interface between a relay        node and a UE.    -   Un interface: This means an interface between a relay node and        an eNB. This interface means an interface used for transmission        and reception performed in MBSFN (MBMS (multimedia        broadcast/multicast services) over single frequency network)        subframe.    -   PC5 interface: This means an interface used for direct        communication between two UEs. This interface is used for        communication between devices supportive of ProSE (proximity        service).    -   DSRC (dedicated shiort range communications): This means a        protocol and standard specification used for short-range or        medium-range wireless communication for vehicles. Communication        is performed using an interface different from the Uu, Un and        PC5 interfaces.

3. Communication Method using Context Information

When the study on LTE system and SAE system has started, the greaterpart of mobile terminals includes few sensors. Hence, a standardspecification has been enacted without a specific consideration on anoperation of a device or a sensor. As a result, a current cellularsystem is unable to sufficiently utilize specific information of such aterminal as a smartphone or a wearable device. Moreover, since thecellular system strictly seeks the separation of each protocol layer ingeneral, it is not easy for network nodes to utilize context informationof a terminal.

Meanwhile, utilization of context information gradually becomes easy. AsOS and applications of an intelligent mobile terminal are disseminated,users tend to give more authority to applications requiring personalinformation and sensor information. In order to improve productivity,users allow applications to access a personal schedule, e-mail, locationinformation, contact information and the like of the users. And, manyadvertisement platforms used for an application provide a user withadvertisement and recommendation information customized to the user viabig data analysis.

In this viewpoint, it is necessary for a next generation network systemto utilize not only context information of a user but also sensorinformation sensed by each of sensors. The information can be utilizedto provide a service optimized to a scenario of each user.

According to a recent trend, a user terminal is implemented by asmartphone. In the aspect of hardware, a smartphone is implemented byincluding a plurality of sensors including an acceleration sensor, agyroscope sensor, a magnetic sensor, an altitude sensor, a proximitysensor, a GPS sensor, and the like. Moreover, the smartphone supportsvarious wireless access technologies including Bluetooth, WiFi, NFC(near field communication), and the like. Information collected by thesensors and the access technologies can be used not only by applicationsof the smartphone but also by a network node. Since many applicationsand operating systems request user permission for accessing contextinformation, it is necessary for a next generation system to havecapability capable of searching for the context information.

In the following, a method of performing communication using contextinformation is explained with reference to embodiments shown in FIGS. 8to 12. First of all, FIGS. 8 and 9 show a legacy communication methodusing context information and explain a background that a proposedembodiment is derived from the legacy communication method.

According to the legacy communication method, since a layer in charge ofcommunication is separated from a layer in charge of an application,interaction between layers is limitative. In particular, according to anOSI 7-layer model, layers positioned below an application layer operatein a state that the layers do not know information transmitted andreceived in the application layer.

However, in order for a communication layer, which is in charge oftransmitting information of the application layer, to more efficientlyoperate, it is necessary for the communication layer positioned belowthe application layer to widely use the information of the applicationlayer. For example, in order to make the communication layer moreefficiently operate, it is necessary for the communication layer toconfigure a prescribed parameter value using external information (e.g.,information of the application layer or hardware information of anentity implementing the communication layer) or utilize the externalinformation for a network operation. As a different example, a currentbeamforming technology adjusts a transmission/reception parameter usinga predetermined signal pattern without a relative position between abase station and a terminal or information on an obstacle. In this case,if the base station is able to know a terminal position and useinformation on a building or an obstacle near the terminal, it may beable to more quickly and efficiently perform beamforming on theterminal. For example, when the base station transmits configurationinformation on environment/parameter to the terminal to applybeamforming, MIMO technique, and the like to the terminal, the basestation can indicate the terminal to transmit information(location/speed/moving direction, etc.) on the terminal to a networkwith a prescribed condition or an interval. Subsequently, the basestation reduces candidates of beams/parameters to be applied to theterminal according to the information on the location/speed/movingdirection, etc. transmitted by the terminal and can promptly determine abest value.

In the following, a problem of the related art shown in FIG. 8 isexplained. It may consider a method of forwarding applicationinformation to an application server corresponding to a terminal end asa method for a wireless communication network to use information of anapplication dynamically performed in a terminal.

First of all, an application layer of a terminal generates informationrelated to an application to configure a data packet and forwards thedata packet to a communication layer of the terminal [S810].Subsequently, the communication layer of the terminal transmits theforwarded data packet to an eNB [S820]. In this case, the eNB can beconfigured to have a new layer for analyzing the data packet of theapplication layer. In particular, the eNB analyzes contents of thereceived data packet, coverts the contents into a value necessary forradio configuration, and informs the terminal of a change of aconfiguration value if necessary. Subsequently, the eNB forwards thedata packet to an SGW [S830]. Similar to the eNB, the SGW analyzescontents of the received data packet, coverts the contents into a valuenecessary for radio configuration, and informs the terminal of a changeof a configuration value if necessary. The SGW forwards the data packetto an application server via a PGW [S840].

The procedures mentioned earlier in FIG. 8 have a limit described in thefollowing. It is necessary for an eNB, an SGW, and an MME to implementan application layer in additional to a legacy communication layer. Adata format used in each application is different according to amanufacturer of an application and an interpretation method is differentas well. Hence, it is necessary to additionally implement theapplication layer in the eNB, the SGW, and the MME to interpretapplication information included in a data packet. However, since aplurality of terminals use a different application and there are manytypes and numbers of an application performing the same role, theabovementioned scheme has a limit in that it is necessary to interpretthe huge number of applications in the eNB, the SGW, and the MME.

And, the application layer uses an encryption scheme configured by eachapplication as it is when peer-to-peer information forwarding isperformed. If information generated by an application of a terminal istransmitted in a manner of being encrypted, since an eNB and an SGW donot have information necessary for decoding a data packet, the eNB andthe SGW are unable to know contents included in the data packet. Inparticular, since the terminal corresponding to a generating side ofinformation and an application server corresponding to a receiving sideof the information know the contents only, it is difficult for a middlenode to know the contents.

In the following, a problem of the related art shown in FIG. 9 isexplained. A scheme of using an SCEF (service capability exposurefunction), i.e., an interworking function laid between 3GPP network andan application server, is explained in FIG. 9.

First of all, an application layer of a terminal transmits applicationinformation to an application server [S910]. The application serverdetermines information regarded as information necessary for acommunication layer of the terminal and transmits a determined result toan SCEF [S920]. The SCEF exists between 3GPP communication network andan external application server and plays a role in providing aninterface. The SCEF forwards information received from the applicationserver to an MME [S930] and the MME forwards the received information toan eNB related to the terminal [S940]. An application layer of the eNBanalyzes the information received from the MME, converts the informationinto a value necessary for radio configuration, and inform the terminalof a change of a configuration value if necessary [S950].

The procedures mentioned earlier in FIG. 6 also have a limit. In theaspect of managing the application server, it is necessary to knowwhether a client using a service of the application server uses 3GPPnetwork or WiFi or fixed broadband to access the application server.This leads to the increase of development cost and complexity. Inparticular, since the operation of FIG. 9 is applied to only a clientaccessing the application server via 3GPP network, if a data packet isreceived from a certain client, it is necessary for the applicationserver to detect whether or not the data packet is received via the 3GPPnetwork. If it is detected that the data packet is received via the 3GPPnetwork, it is necessary for the application server to detect whether ornot the data packet is received through a 3GPP service providersupporting the SCEF. Since the 3GPP network is connected with anexternal internet in wired, it is difficult for the application serverto know whether or not a client uses the 3GPP network.

Moreover, if a communication layer utilizes information of anapplication layer, it may obtain such a gain as battery saving of aterminal, 3GPP network resource optimization, and the like. The gaincorresponds to a gain between a network and a terminal. In the aspect ofa manager of the application server, the manager has almost no gain.Hence, the scheme described in FIG. 9 has a limit in that it isdifficult to practically apply the scheme.

In the following, a proposed embodiment is explained in consideration ofthe aforementioned problems with reference to FIGS. 10 to 12. Accordingto the proposed embodiment, a terminal and a network entity exchangecontext information with each other. The network entity may correspondto various communication nodes participating in a procedure of providinga service to the terminal such as an eNB, an MME, an SGW, a PGW, anapplication server, and the like.

First of all, when the terminal accesses a network, the terminal informsthe network entity of whether or not the terminal has capability capableof transceiving context information with the network entity. Thisprocedure can be initiated using signaling signaled by the networkentity to query context information to be informed by the terminal. Forexample, the network entity can query the context information to beinformed by the terminal by transmitting a context capability querymessage to the terminal.

Subsequently, the terminal informs the network entity of whether or notthe terminal has capability capable of informing the network entity ofthe context information in response to the query of the network entity.The terminal can also inform the network entity of a type of the contextinformation. This procedure can be performed by transmitting a contextcapability response message.

Meanwhile, information indicating a type of context information to betransmitted to the network entity is referred to as context typeinformation. An indicator indicating the type of the context informationto be transmitted to the eNB can be configured in advance. For example,location information and schedule information can be mapped to a‘location’ indicator and a ‘calendar’ indicator, respectively. Inparticular, if the indicator indicating the context type information istransceived between the terminal and the network entity, the terminaland the network entity can efficiently transceive the context typeinformation with each other. Meanwhile, the terminal and the networkentity ignore context type information not supported by the terminal andthe network entity or context type information incapable of beingunderstood by the terminal and the network entity. Although the contexttype information not supported or incapable of being understood by theterminal and the network entity is received, the context typeinformation is not processed.

The network entity may not charge for a data packet used for forwardingthe context information and the context type information. Or, thenetwork entity may exclude the charge from the total charged amount.Hence, the amount of context information provided by a user mayincrease.

Having received a response for context information capable of beinginformed by the terminal, the network entity transmits configurationinformation to the terminal to inform the terminal of a type and timingof context information to be transmitted. The terminal transmits contextinformation to the network entity according to the configurationinformation. This procedure can be performed by transceiving a contextrequest message and a context response message between the terminal andthe network entity. When the network is periodically triggered or istriggered by a specific event, the network can transmit theconfiguration information to the terminal to make the terminal transmitthe context information. In this case, if a type of context informationrequested by the network entity corresponds to information not allowedby a user of the terminal, the terminal may discard or reject therequest of the network entity. If whether or not the user allows a typeof context information is not determined yet, the terminal may inquireof the user about whether or not the type of the context information isallowed.

The network entity provides a service to the terminal by utilizing thecontext information received from the terminal. Specifically, thenetwork entity can utilize the context information for scheduling theterminal, allocating a resource, and the like. For example, the terminalcan inform the network entity of schedule information (specifically,time and location information) of a user as the context information.Having received the context information, the network entity cananticipate the amount of data access to be occurred at specific locationat specific timing based on schedule information collected fromterminals which have accessed a network of the network entity. Moreover,the network entity can perform resource reservation based on theanticipated result. The network entity can perform the resourcereservation in consideration of frequency amount to be used by cells ofa corresponding area.

A certain frequency spectrum can be flexibly assigned via auctionbetween service providers in a time unit instead of being fixedlyassigned to a specific service provider. In this case, if a frequencyamount assigned to a service provider of a network at specific time anda specific region is less than the sum of frequency amounts required byterminals supported by the service provider, the service provider maywant to additionally receive a spectrum.

As a different example, a terminal having a special purpose may inform anetwork entity of context information indicating a moving path of theterminal. The special terminals can inform the network entity ofinformation on a moving path of the terminal and information on timetaken for moving permitted by a related organization.

The network entity allocates and reserves a network resource to beprovided to the terminal based on the information on the moving path andthe information on the moving time received from the terminal.Specifically, the network entity checks cells through which the movingpath of the terminal is passed and informs each of the cells of anamount of resource to be allocated to the terminal and resourceallocation timing. A resource is allocated to each of the cells inadvance. Each of the cells reserves a resource in advance for theterminal and informs the network entity of a result of the resourcereservation. If a resource to be allocated to the terminal is reserved,the network entity informs the terminal of information on the reservedresource. For example, the network entity can inform the terminal ofinformation on a cell from which a resource is to be allocated andtiming of resource allocation. When the terminal moves along with amoving path, the terminal receives a resource from the network in amanner of being connected with the network based on the informationreceived from the network entity and receives a service from thenetwork.

In FIG. 10, the aforementioned procedures are explained in detail. Anembodiment shown in FIG. 10 explains a procedure of optimizing a networkparameter or a radio parameter by processing information obtained fromlayers other than a communication layer of a terminal via a framework ofthe communication layer without depending on an application server.

First of all, a terminal performs a procedure of attaching to a network.The terminal transmits an attach request message to an MME [S1005]. Inthis case, the attach request message can include information on contextcapability of the terminal. FIG. 10 illustrates an example ofinformation (context capable=yes) indicating that the terminal is ableto inform the network of the context capability information. Accordingto one embodiment of the present invention, when the terminal transmitsthe attach request message to the MME, the terminal can also inform theMME of a type of context information capable of being supported by theterminal. FIG. 10 illustrates an example that the terminal is able toinform the MME of location information and schedule information.

Meanwhile, the terminal can inform a network of context information bymapping the context information to a prescribed value according to atype of the context information. For example, location information andschedule information can be mapped to ‘0001’ and ‘0002’, respectively.In order for the terminal to indicate context information supported bythe terminal, the terminal can transmit information indicating the‘0001’ and the ‘0002’ to the MME.

The MME checks that the terminal has context capability based on theinformation included in the attach request message received from theterminal and checks that the terminal is able to support locationinformation and schedule information. The MME compares the informationwith information preoccupied by the MME. If necessary, the MME updatesinformation relates to the context of the terminal and forwardscontext-related information to an HSS [S1010].

Subsequently, the MME performs an S1 UE setup procedure to an eNB toforward the context-related information of the terminal to the eNB[S1015]. In this case, the MME can transmit a message including contextcapability information and context type information of the terminal tothe eNB.

The eNB recognizes that the terminal is able to transmit contextinformation based on the information received form the MME. Hence, theeNB additionally transmits a context request message to the terminal toask the terminal to transmit context information [S1020]. In this case,the eNB designates a specific context type (e.g., ‘schedule information’or ‘0002’) among the context information supported by the terminal toindicate the terminal to transmit schedule information of a user.

Having received the context request message, the terminal collectsinformation related to the schedule information of the user from astoring region of the terminal, a memory, an application, a sensor, andthe like and coverts the collected information into a designated format.The terminal includes the schedule information in a context responsemessage and transmits the context response message to the eNB [S1030].

The eNB checks eNBs related to the movement of the terminal using theinformation received from the terminal. For example, each serviceprovider can separately configure a DB to manage information of eNBsrelated to a specific location and the eNB can inquire of the DB aboutan eNB related to the terminal [S1035].

If the eNBs related to the terminal are selected based on the contextinformation of the terminal, the eNB transmits the context informationof the terminal to the selected eNBs (eNB 1 and eNB2) [S1040, S1050].This procedure can be performed via a procedure of transmitting aresource reservation message. The resource reservation message caninclude time anticipated according to a schedule of the terminal andinformation on an anticipated resource amount.

Having received the resource reservation message, the eNB1 determinesthat the eNB1 has no problem in supporting the terminal in considerationof a resource management status of the eNB 1. Subsequently, the eNB 1transmits a resource reservation response message to the eNB and checksthat a resource is reserved [S1045].

Having received the resource reservation message, the eNB 2 anticipatesthat resources of the eNB 2 are going to be insufficient when theterminal enters a region managed by the eNB 2. In this case, the eNB 2accesses a server (in FIG. 10, spectrum allocation server) configured tomanage radio resources and may ask the server to allocate an additionalradio resource to the eNB 2 when the terminal enters the region managedby the eNB 2 [S1055]. The eNB 2 can prevent a shortage of radioresources in advance via the aforementioned procedure. The eNB 2 asksthe server to allocate a radio resource and may be than able to transmita resource reservation response message to the eNB to indicate that aresource has been reserved [S1060].

The eNB can optionally forward a result for the steps S1040 to S1060 tothe terminal [S1065]. For example, the eNB 1 and the eNB 2 set a radioparameter (e.g., C-RNTI, etc.) to the terminal at the timing accordingto schedule information of a user and can transmit preconfiguredinformation to the eNB. When the eNB transmits the radio parameter,which is included in the information received from the eNB 1 and the eNB2, to the terminal, if the terminal enters regions managed by the eNB 1and the eNB 2, the terminal may be able to immediately use preassignedC-RNTI without additionally performing cell update or a handoverprocedure. For example, if a radio resource allocation message istransmitted using C-RNTI preassigned by the eNB 1, the terminal canreceive the radio resource allocation message using predeterminedC-RNTI.

According to one embodiment of the present invention, if contextcapability information is included in the attach request messagementioned earlier in the step S1005, the attach request message can beimplemented as shown in Table 2 in the following. In Table 2, a contextcapability list field can include values indicating types of contextinformation capable of being supported by the terminal.

TABLE 2 Information IEI Element Type/Reference Presence Format LengthProtocol Protocol discriminator M V ½ discriminator 9.2 SecuritySecurity header type M V ½ header type 9.3.1 . . . . . . . . . . . . . .. UE Context Context Capability O TLV Capability List

In the following, a method of supplementing the aforementionedembodiment is explained. In the foregoing description, a process that aterminal transceives information with a network entity in a manner thata code (or, a value) is mapped to each context type and the code istransmitted and received in a signaling procedure has been explained.Yet, as a terminal is evolving, a context type supported by each releasecan be differentiated. Simply, the number of context types supported bya recently released terminal could be less than the number of contexttypes supported by a terminal to be released in several years. It is thesame for a network entity including an eNB. For example, a terminalsupports context codes ‘0001’ and ‘0002’ only, whereas a network entitysupports ‘0001’, ‘0002’, and ‘0003’. An opposite case is also available.

Due to the mismatch, if the network entity requests information on acontext code not supported by the terminal, the terminal may consider itas an error occurs on context capability forwarded to a network by theterminal. In this case, the terminal immediately retransmits theinformation on the context capability of the terminal to the network. Ingeneral, the terminal transmits the information on the contextcapability to an eNB after a request for the information is receivedfrom the eNB. Hence, if the information is received from the terminalalthough the information is not requested, the eNB considers it as anerror occurs and disconnects an RRC connection. In order to solve theproblem, if the eNB asks the terminal to transmit a context type notsupported by the terminal, the terminal immediately transmitsinformation on context types supported by the terminal to the eNB.Moreover, the terminal includes a value indicating‘receptionOfIncorrectType’ in an updateCuase field of a message andtransmits the message. By doing so, the terminal can inform the eNB thatthe eNB has requested an incorrect context type to the terminal. Bydoing so, it may be able to resolve a problem that the eNB disconnectsan RRC connection with the terminal.

In the following, a different embodiment is explained. In the foregoingembodiments, the eNB requests schedule information of the terminal toreserve resources of eNBs in advance according to a movement of theterminal. Yet, when the eNB reserves resources of the eNB 1 and the eNB2 according to information received from the terminal, the eNB 1 or theeNB 2 may fails to reserve a resource in accordance with moving timingof the terminal. In this case, the eNB may inform the terminal of thereservation failure. In a legacy communication system, since acommunication network was unable to know context information such asmovement information of the terminal, the terminal recognizes a shortageof resource via an attach failure only after the terminal moves to acell where resources are practically insufficient. On the contrary,according to the aforementioned embodiment, the eNB informs the terminalthat it is unable to reserve a resource of the eNB 1 or a resource ofthe eNB 2 and attempts to reserve a radio resource to a different eNBother than the two eNBs or informs the terminal that radio access is notsmooth at corresponding timing. In this case, the terminal does notperform an operation of worsening a shortage of radio resource such asan operation of unnecessarily attempting to perform radio access inregions managed by the eNB 1 and the eNB 2.

A procedure for the eNB to inform the terminal of the failure ofresource reservation can be performed in the step S1065 of FIG. 10. TheeNB transmits a message including information such as ‘preconfigurationfailure’ to the terminal and includes information on a region, an eNB ortime at which a radio resource is not allocated in the message. When theradio resource reservation failure is notified to the terminal, if theterminal camps on the region or the eNB, the terminal does not perform anew RRC connection request procedure during designated time.

In the foregoing description, the terminal transmits context informationto the network via a procedure of transmitting an attach request messageto the MME. On the contrary, it may update an eNB only except the MMEaccording to a selection of a service provider. In this case, in orderto make the eNB utilize the context information of the terminal, it isnecessary for the eNB to directly ask the terminal to transmit contextcapability. In particular, if the eNB sets such an item as‘ContextCapability’ to a ‘UECapabilityEnquiry’ message and transmits themessage to the terminal, the terminal transmits a‘UECapabilityInformation’ message including a context type supported bythe terminal to the eNB.

Table 3 in the following shows an example of implementing the‘UECapabilityEnquiry’ message via RRC signaling and Table 4 in thefollowing shows an example of implementing the ‘UECapabilityInformation’message via RRC signaling.

TABLE 3 -UECapabilityEnquiry The UECapabilityEnquiry message is used torequest the transfer of UE radio access capabilities for E-UTRA as wellas for other RATs. Signalling radio bearer: SRB1 RLC-SAP: AM Logicalchannel: DCCH Direction: E-UTRAN to UE UECapabilityEnquiry message   --ASN1START   UECapabilityEnquiry ::=     SEQUENCE {   rrc-TransactionIdentifier RRC-TransactionIdentifier,   criticalExtensions        CHOICE {       c1    CHOICE {          ueCapabilityEnquiry-r8    UECapabilityEnquiry-r8-IEs,          spare3 NULL, spare2 NULL, spare1 NULL           },      criticalExtensionsFuture     SEQUENCE { }    }   }  UECapabilityEnquiry-v1310-IEs ::= SEQUENCE {   nonCriticalExtensio    UECapabilityEnquiry-   V1XYZ-IEs { }           OPTIONAL   }  UECapabilityEnquiry-v1XYZ-IEs ::= SEQUENCE {   requestedContextCapability     ENUMERATED {true} OPTIONAL,    updateCause    ENUMERATED(receptionofincorrectType,reserved,reserved,reserved)   nonCriticalExtension     SEQUENCE  OPTIONAL   }  UE-CapabilityRequest ::=     SEQUENCE (SIZE (1..maxRAT−  Capabilities)) OF RAT-Type   -- ASN1STOP UECapabilityEnquiry fielddescriptions - requestedContextCapability indicates that the UE shallexcplicitly indicate whether it supported context reporting.

TABLE 4 -UECapabilityInformation The UECapabilityInformation message isused to transfer of UE radio access capabilities requested by theE-UTRAN. Signalling radio bearer: SRB1 RLC-SAP: AM Logical channel: DCCHDirection: UE to E-UTRAN UECapabilityInformation message   -- ASN1START  UECapabilityInformation-v1250-IEs ::= SEQUENCE {   ue-RadioPagingInfo-r12  UE-RadioPagingInfo-r12 OPTIONAL,   nonCriticalExtension  UECapabilityInformation-   v1XYZ-IEs { }        OPTIONAL   }   UECapabilityInformation-v1XYZ-IEs ::= SEQUENCE {   ue-contextCapabilityInfo      UE-   ContextCapabilityInfo  OPTIONAL,   nonCriticalExtension  SEQUENCE { }    OPTIONAL   }  UE-ContextCapabilityInfo :: = SEQUENCE {    supportedCapabilityInfo   ENUMERATED {true} OPTIONAL,    supportedCapabilityType   SEQUENCE (SIZE (1..maxType−Context))   OF ContextType   }   --ASN1STOP UECapabilityInformation field descriptions-SupportedCapabilityInfo Indicates whether the UE supported ContextReporting -ContextType Indicates the supported context reporting. I.e.,0001 indicates location, 0002 indicates schedule, 0003 etc

FIG. 11 is a diagram for explaining a server (a spectrum allocationserver mentioned earlier in FIG. 10) configured to manage a radioresource.

As a mobile internet service continues to expand, discussion on aconcept such as LSA (Licensed Shared Access) and ASA (Authorized SharedAccess) is in progress. According to a legacy mobile communicationnetwork model, if government assigns a frequency to a mobilecommunication service provider, the service provider provides acommunication service to a user based on the assigned frequency. In thiscase, since the number of subscribers is different according to aregion, the amount of frequencies required by a service provider isdifferent according to a region. And, one service provider may requiremore frequencies at a specific region at specific time according to acharacteristic of a subscriber, whereas another service provider maynot. According to a legacy frequency assignment model, although afrequency requirement is variously changed over time, since the fixedand constant amount of frequencies are assigned, frequency resources areinefficiently used.

Discussion on the introduction of the LSA/ASA is in progress in theUnited States and the Europe centering on 3.5 GHz and 2.5 GHz bands. Forexample, in the United States, since 3.5 GHz band is used by a coastguard, the band is necessary in a coast area only. Hence, the frequencyband can be assigned for the use of mobile communication in an inlandarea. And, even in a coast area, a frequency is necessary only whencommunication is practically performed between a ship and a coastguardstation and the frequency is not necessary during other times. Inparticular, according to the LSA/ASA scheme, the frequency band ispreferentially used by the coast guard and the frequency band isdynamically assigned to a mobile communication service provider duringthe time not used by the coast guard.

In particular, in order to provide a satisfactory mobile communicationservice to subscribers of a service provider, if a frequency fixedlyassigned to the service provider is insufficient at a specific region, atemporary frequency can be additionally assigned to the serviceprovider. To this end, the LSA/ASA may prepare a frequency allocationserver (in FIG. 11, ‘spectrum allocation server’) and the frequencyallocation server can temporarily assign a frequency to serviceproviders when the service providers need an additional frequency.

Meanwhile, when the abovementioned operation is performed, it isnecessary for a network service provider to receive a frequency from afrequency allocation server before a shortage of frequency actuallyoccurs. To this end, it is important for a mobile communication serviceprovider to anticipate the timing at which a demand of frequency isgenerated. In particular, it is important for network entities toutilize the context information of the terminal according to theaforementioned embodiments.

It is able to efficiently utilize frequencies by utilizing the contextinformation of the terminal in a mobile communication system through theaforementioned embodiments. Moreover, it is able to solve a problem ofunnecessarily securing a frequency as well.

FIG. 12 illustrates a further different embodiment corresponding to avariation of the proposed embodiment.

Discussion on various concepts for more flexibly using a system resourceis in progress in a next generation 5G communication system. Forexample, the concepts may include NFV (Network Function Virtualization),SDN (Software Defined Radio), Network slicing, and the like.

According to a legacy communication system, each of nodes is implementedby a dedicatedly configured and designed hardware device. For example,such a node as an MME, an SGW, an eNB, or the like is implemented by asingle physical device. Hence, it is necessary for a service providerintending to configure a simple network to have an MME, an SGW, and aneNB, respectively. Subsequently, if the number of service subscribersincreases, the service provider may have an additional network entity byanticipating user demand and configure a network.

For example, assume a case that an MME supports 100 users, an SGWsupports 50 users or 100 Mbps, and an eNB supports 50 Mbps. If a serviceprovider secures 50 users and each of the users use average 1 Mbps, theMME/SGW/eNB can averagely support all of the users. Yet, depending on asituation, if a request for a specific video is explosively increasedand demand of users is increased up to 2 Mbps, capacity of the eNBbecomes insufficient. Hence, the service provider installs 2 eNBs byassuming a worst scenario. However, this also cause a problem. Due tothe movement of the users or a geographical difference, the users maynot be evenly distributed to the two eNBs. It is necessary for theservice provider to avoid a worst situation by additionally installingan eNB in consideration of the abovementioned case.

Yet, in case of considering average data use amount of a user, it mayfrequently have a chance of not using the additionally installed eNBs ormay have load not reaching the maximum design value. Hence, theadditionally installed eNBs may become a reason of investment waste forthe service provider. In case of considering roaming of a user, asubscriber of a different service provider may access a network of theservice provider. Hence, it is necessary for the service provider toadditionally install an SGW in preparation for the roaming of the user.In case of considering a case that the service provider continuouslysecures a subscriber, it is necessary for the service provider toadditionally install an SGW. In this situation, the SGW is also usedwith a rate lower than an acceptance value of the service provider.

In summary, since nodes are fixed in a hardware manner in a legacysystem, it was not able to make the best use of each hardwarecapability. This problem is burden to management cost and installationcost of a service provider.

Yet, in recent years, a cloud concept has been developed centering oninternet service providers. In particular, an internet service providerimplements software of the internet service provider not directlymanaging an internet server device but using hardware of a cloud serviceprovider and pays cost for as much as an amount of using a hardwareresource. By doing so, the internet service providers can reducehardware installation cost and management cost.

Similarly, a cloud concept has been introduced to a process of designing5G communication system. In particular, hardware and a network resourceare flexibly managed using cloud and a resource is flexibly usedaccording to each network load. Specifically, if resources of an eNB areinsufficient (i.e., if the number of users allocated to the eNBincreases or average data use amount increases), the cloud increases theresource amount allocated to the eNB (e.g., network bandwidth, frequencyamount, CPU calculation amount). On the contrary, if the resources ofthe eNB are left (i.e., if the number of users allocated to the eNBdecreases or average data use amount decreases), the cloud decrease theresource amount allocated to the eNB.

In a broad sense, if terminals belonging to a specific service providerperform more signaling-related procedures, it may deploy more cloudresources to an MME and deploy less resource to an eNB, and vice versa.In particular, it may have various configurations. It is advantageous inthat it is able to easily control resources of network entities at anytime compared to a case of increasing a physical node. In particular,according to a legacy scheme, if resources of an eNB are not sufficient,there is a burden that a new physical eNB is practically deployed. Onthe contrary, if resources are managed in a software manner using acloud scheme, it may be able to deploy an additional eNB within secondsor easily increase capacity of a legacy eNB.

Legacy network devices are physically separated and designed andmanufactured in a manner of being optimized to each node, because oflegacy CPU performance. In particular, since the CPU performance is low,a DSP (digital signal processor) optimized for a role of each node isused and a very fast wired backbone network configuration was expensive.Yet, as the CPU performance is developing and network backboneperformance is enhanced, the cloud scheme becomes available in acommunication system as well.

In particular, since network resources are used via a cloud scheme, itis necessary for a service provider to optimize a procedure ofdistributing resources to each network node and a procedure ofadding/eliminating a resource according to a necessity. For example, incase of a housing area and a commercial area, people stay at the housingarea from night to morning and stay at the commercial area such asoffice, school, and the like from morning till night. In this case, anetwork service provider may add physical eNBs in a manner that theservice provider distributes more radio resources to the commercial areaduring the daytime and distributes more radio resources to the housingarea at night. As a different example, it may distribute more radioresources to outdoor (valley, beach, etc.) in the summer and distributemore radio resources to indoor in the winter.

In order to perform the abovementioned scheme, it is necessary for aservice provider and a network to utilize contexts of users. Inparticular, if schedule information corresponding to context informationtransmitted by a terminal is forwarded to a network, the network is ableto know a data amount required by a user at a certain region. Based onthis, the network is able to determine a region to which a cloudresource is to be additionally allocated and an amount of the cloudresource. Moreover, the network can determine an amount of resources tobe additionally secured.

FIG. 12 illustrates the aforementioned procedures. In FIG. 12, the stepsS1205 to S1230 are similar or identical to the steps of FIG. 10,explanation on a specific procedure is omitted at this time.

If an eNB obtains context information of a terminal according tosignaling with the terminal, the eNB forwards the context information ofthe terminal to a resource management node configured to manage anetwork resource [S1235]. The resource management node shown in FIG. 12may correspond to a spectrum allocation server or the aforementionednetwork node configured to manage the cloud resource. The resourcemanagement node determines a network entity where resource allocation isto be controlled using the received context information.

The resource management node additionally allocates a resource to an eNB1 based on context information indicating that the terminal is going tomove to a region related to the eNB 1 [S1240]. Or, if the eNB 1 has anupper limit of radio resources, the resource management server mayallocate a radio resource or an additional cell to a different eNB whichis positioned at a region at which the eNB 1 is located. And, theresource management node may reserve radio resource allocation for theterminal in an eNB 2 based on context information indicating that theterminal is going to move to a region at which the eNB 2 is located[S1245].

4. Device Configurations

FIG. 13 is a diagram illustrating configurations of node devicesaccording to a proposed embodiment.

A user equipment (UE) 100 may include a transceiver 110, a processor120, and a memory 130. The transceiver 110 may be configured to transmitand receive various signals, data, and information to/from an externaldevice. Alternatively, the transceiver 110 may be implemented with acombination of a transmitter and a receiver. The UE 100 may be connectedto the external device by wire and/or wirelessly. The processor 120 maybe configured to control overall operations of the UE 100 and processinformation to be transmitted and received between the UE 100 and theexternal device. Moreover, the processor 120 may be configured toperform the UE operation proposed in the present invention. The memory130, which may be replaced with an element such as a buffer (not shownin the drawing), may store the processed information for a predeterminedtime.

Referring to FIG. 13, a network node 200 according to the presentinvention may include a transceiver 210, a processor 220, and a memory230. The transceiver 210 may be configured to transmit and receivevarious signals, data, and information to/from an external device. Thenetwork node 200 may be connected to the external device by wire and/orwirelessly. The processor 220 may be configured to control overalloperations of the network node 200 and process information to betransmitted and received between the network node device 200 and theexternal device. Moreover, the processor 220 may be configured toperform the network node operation proposed in the present invention.The memory 230, which may be replaced with an element such as a buffer(not shown in the drawing), may store the processed information for apredetermined time.

The specific configurations of the UE 100 and the network node 200 maybe implemented such that the aforementioned various embodiments of thepresent invention can be independently applied or two or moreembodiments can be simultaneously applied. For clarity, redundantdescription will be omitted.

The embodiments of the present invention may be implemented usingvarious means. For instance, the embodiments of the present inventionmay be implemented using hardware, firmware, software and/or anycombinations thereof.

In case of the implementation by hardware, a method according to eachembodiment of the present invention may be implemented by at least oneselected from the group consisting of ASICs (application specificintegrated circuits), DSPs (digital signal processors), DSPDs (digitalsignal processing devices), PLDs (programmable logic devices), FPGAs(field programmable gate arrays), processor, controller,microcontroller, microprocessor and the like.

In case of the implementation by firmware or software, a methodaccording to each embodiment of the present invention can be implementedby modules, procedures, and/or functions for performing theabove-explained functions or operations. Software code may be stored ina memory unit and be then executed by a processor. The memory unit maybe provided within or outside the processor to exchange data with theprocessor through the various means known to the public.

As mentioned in the foregoing description, the detailed descriptions forthe preferred embodiments of the present invention are provided to beimplemented by those skilled in the art. While the present invention hasbeen described and illustrated herein with reference to the preferredembodiments thereof, it will be apparent to those skilled in the artthat various modifications and variations can be made therein withoutdeparting from the spirit and scope of the invention. Therefore, thepresent invention is non-limited by the embodiments disclosed herein butintends to give a broadest scope matching the principles and newfeatures disclosed herein.

INDUSTRIAL APPLICABILITY

Although the communication method are described centering on examplesapplied to 3GPP LTE system, it may also be applicable to variouswireless communication systems including IEEE 802.16x and 802.11xsystem. Moreover, the proposed method can also be applied to mmWavecommunication system using a microwave frequency band.

What is claimed is:
 1. A method of performing communication, which isperformed by a base station using context information of a terminal in awireless communication system, the method comprising: receiving amessage comprising context capability information indicating whether ornot the terminal provides context information and context typeinformation indicating a type of the context information supported bythe terminal from a network entity; transmitting a context requestmessage for requesting specific context information among the contextinformation supported by the terminal to the terminal; receiving fromthe terminal, a context response message comprising context informationwhich is generated based on information generated in an applicationlayer of the terminal; and changing a configuration value of a radioresource based on the context information.
 2. The method of claim 1,wherein the changing comprises: selecting different base stationsrelated to the terminal based on the context information; andtransmitting a resource reservation message for requesting reservationof a radio resource for the terminal to the different base stations. 3.The method of claim 2, further comprising: receiving a resourcereservation response message indicating that the reservation of theradio resource for the terminal is authorized from the different basestations; and informing the terminal of the completion of thereservation of the radio resource.
 4. The method of claim 2, wherein thecontext information contained in the context response message comprisesat least one selected from the group consisting of schedulinginformation, location information, and time information of a user of theterminal.
 5. The method of claim 4, wherein the reservation of the radioresource is reserved for the terminal by a prescribed base station at aprescribed location at prescribed time according to the contextinformation contained in the context response message.
 6. The method ofclaim 2, wherein if a base station among the different base stations isunable to reserve a radio resource according to the resource reservationmessage, the base station asks a network entity configured to manageradio resources to allocate an additional radio resource.
 7. The methodof claim 1, wherein the network entity corresponds to an MME (mobilitymanagement entity).
 8. A base station performing communication usingcontext information of a terminal in wireless communication environment,the base station comprising: a transmitter; a receiver; and a processoroperates in a manner of being connected with the transmitter and thereceiver, wherein the processor: receives a message comprising contextcapability information indicating whether or not the terminal providescontext information and context type information indicating a type ofthe context information supported by the terminal from a network entity;transmits a context request message for requesting specific contextinformation among the context information supported by the terminal tothe terminal; receives from the terminal, a context response messagecomprising context information which is generated based on informationgenerated in an application layer of the terminal; and transmits aresource reservation message for requesting reservation of a radioresource for the terminal to different base stations which are selectedbased on the context information.
 9. The base station of claim 8,wherein the processor is configured to select the different basestations related to the terminal based on the context information andtransmit the resource reservation message for requesting the reservationof the radio resource for the terminal to the different base stations.10. The base station of claim 9, wherein the processor is configured toreceive a resource reservation response message indicating that thereservation of the radio resource for the terminal is authorized fromthe different base stations and inform the terminal of the completion ofthe reservation of the radio resource.
 11. The base station of claim 9,wherein the context information contained in the context responsemessage comprises at least one selected from the group consisting ofscheduling information, location information, and time information of auser of the terminal.
 12. The base station of claim 11, wherein thereservation of the radio resource is reserved for the terminal by aprescribed base station at a prescribed location at prescribed timeaccording to the context information contained in the context responsemessage.
 13. The base station of claim 9, wherein if a base stationamong the different base stations is unable to reserve a radio resourceaccording to the resource reservation message, the base station asks anetwork entity configured to manage radio resources to allocate anadditional radio resource.
 14. The base station of claim 8, wherein thenetwork entity corresponds to an MME (mobility management entity).